Deno: Denial of service via non-ASCII bytes in WebSocket response headers_CVE-2026-55517

{
    "lastseen": "",
    "description": "Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response headers in a way that assumed their bytes were always printable ASCII. A response header containing non-visible-ASCII bytes (0x80-0xFF) caused a panic that aborted the entire Deno process. This vulnerability is fixed in 2.7.5.",
    "published": "2026-06-23T17:24:59.498Z",
    "modified": "2026-06-23T17:52:56.960Z",
    "type": "cve",
    "title": "Deno: Denial of service via non-ASCII bytes in WebSocket response headers",
    "source": "GitHub_M",
    "references": "https://github.com/denoland/deno/security/advisories/GHSA-x2qc-cmh9-f4hf",
    "id": "CVE-2026-55517",
    "bulletinFamily": "",
    "cwe": [
        "CWE-248"
    ],
    "cvelist": null,
    "sourceData": "denoland deno < 2.7.5",
    "sourceHref": "",
    "cvss": {
        "score": 4.3,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "deno",
    "version": "< 2.7.5",
    "vendor": "denoland",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}